1. Field of the Invention
The present invention relates to an optical fiber telecommunications network and more particularly, towards a method and apparatus for extending optical fiber in such a network to the subscriber's neighborhood.
2. Description of the Prior Art
Optical fibers are rapidly becoming the preferred means for transmission in telecommunications networks. The advantages of using optical fibers are well known and are fully accepted as being desirable. Optical fiber transmission provides the potential for exceedingly wide bandwidths which will allow for the future provision of broadband services directly to individual subscribers on a relatively universal basis. Such broadband services may include data transmission; however, there is a broader market for the distribution of video services over the telecommunications network to the vast number of residential subscribers.
In order to achieve the benefits of this broadband capability of optical fibers, it is essential that the fibers be deployed relatively close to the subscriber, as it is difficult to sustain the broadband transmission over great distances using electrical signals. At present, feeder fibers are used to bring telecommunications signals to a Digital Loop Carrier (DLC) Remote Terminal (RT); however, commercially-acceptable methods for providing optical signals closer to the subscriber have not yet been achieved on a reasonably broad basis.
There have been many proposals for providing fiber optic services to residential subscribers in both narrowband and broadband format. Some of these proposals have been described in the Description of the Prior Art set forth in the afore-mentioned co-pending application entitled, "Switched Video Architecture for an Optical Fiber-to-the-Curb Telecommunication System". Various articles have been published describing the advantages of fiber optic systems, and in particular, the advantages of certain types of broadband fiber optic systems.
An article entitled: "A Future Switched Video System" by John R. Gunter, IEEE LCS Magazine, February, 1990, at page 66 and following, describes the desirability of providing video services over the telecommunications network. Another article entitled: "A High-Quality Switched FM Video System" by David E. Robinson and David Grubb, III, IEEE LCS Magazine, also published February, 1990, at page 53 and following describes a proposed system architecture wherein the various video channels are frequency multiplexed onto a carrier; however, the carrier uses wavelength division multiplexing for upstream and downstream transmissions.
Other articles describing the simultaneous transmission of narrowband and broadband signals are as follows: "A Hybrid Lightwave Transmission System for Subcarrier Multiplexed Video and Digital B-ISDN Services in the Local Loop" by Charles N. Lo, Journal of Lightwave Technology, Vol. 7, No. 11, November 1989, pp. 1839-1848; and "Fiber Optic Analog-Digital Hybrid Signal Transmission Employing Frequency Modulation", by K. Sato et al, IEEE Transactions on Communications, Vol. COM-33, No. 5, May 1985, pp. 433-441.